Background: Serum free light chain testing incorporating kappa (κ), lambda (λ) and the involved:uninvolved ratio (rFLC) underpins diagnosis and risk stratification in plasma cell dyscrasias. As clinical cut-offs are derived from the Freelite assay and New South Wales (NSW) laboratories now use N-latex, a comparison is required to guide clinical interpretation.
Kwan et al. (Sun,) studied this question.